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A262076 The first of seven consecutive positive integers the sum of the squares of which is equal to the sum of the squares of thirteen consecutive positive integers. 4
26, 598, 90688, 1891916, 285495236, 5955760408, 898738921678, 18748731881906, 2829229839956546, 59021002008489118, 8906414637444294568, 185798095573991870996, 28037390449444799352956, 584892345845924401415728, 88261696228437590918820358 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For the first of the corresponding thirteen consecutive positive integers, see A262077.

LINKS

Colin Barker, Table of n, a(n) for n = 1..572

Index entries for linear recurrences with constant coefficients, signature (1,3148,-3148,-1,1).

FORMULA

a(n) = a(n-1)+3148*a(n-2)-3148*a(n-3)-a(n-4)+a(n-5) for n>5.

G.f.: -26*x*(x^4+22*x^3+317*x^2+22*x+1) / ((x-1)*(x^4-3148*x^2+1)).

EXAMPLE

26 is in the sequence because 26^2 + ... + 32^2 = 5915 = 15^2 + ... + 27^2.

MATHEMATICA

LinearRecurrence[{1, 3148, -3148, -1, 1}, {26, 598, 90688, 1891916, 285495236}, 20] (* Vincenzo Librandi, Sep 11 2015 *)

PROG

(PARI) Vec(-26*x*(x^4+22*x^3+317*x^2+22*x+1)/((x-1)*(x^4-3148*x^2+1)) + O(x^20))

(MAGMA) I:=[26, 598, 90688, 1891916, 285495236]; [n le 5 select I[n] else Self(n-1)+3148*Self(n-2)-3148*Self(n-3)-Self(n-4)+Self(n-5): n in [1..20]]; // Vincenzo Librandi, Sep 11 2015

CROSSREFS

Cf. A262074, A262075, A262077.

Sequence in context: A293612 A197123 A203598 * A057010 A217636 A249863

Adjacent sequences:  A262073 A262074 A262075 * A262077 A262078 A262079

KEYWORD

nonn,easy

AUTHOR

Colin Barker, Sep 10 2015

STATUS

approved

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Last modified September 25 06:32 EDT 2020. Contains 337335 sequences. (Running on oeis4.)